Danny Hoesen's opener proved to the difference at the interval, before Viktor Fischer provided Frank de Boer's side with breathing space and Davy Klaassen completed the scoring 11 minutes from time.
It may only be a temporary residence in a familiar spot for Ajax, with their advantage standing at one point over Vitesse before the latter’s clash with Go Ahead Eagles on Sunday.
Ajax benefitted from Vitesse's fellow high-flyers AZ slipping up in a bad-tempered 2-2 draw at home to Roda JC.
AZ found remarkably found themselves down to nine men inside the first 20 minutes with Nick Viergever and Nemanja Gudelj receiving their marching orders.
Incredibly, Dick Advocaat's side claimed a 25th-minute lead through Mattias Johansson, but Wiljan Pluim soon restored parity.
AZ were unperturbed and scored again to lead at the break through Aron Johannsson's effort, however Vasil Shkurti provided the penultimate twist with an injury time equaliser – Roda going on to finish a man down after Bart Biemans collected a second yellow card.
Injury-time goals and red cards were seemingly the order of the day with both also occurring in the 1-1 draw between PSV and Heerenveen at the Philips Stadion.
Joey van den Berg left his visiting team-mates to play 75 minutes without him but they looked to have snatched a winner with 10 to go as Yanic Wildschut.
But the hosts' numerical advantage told as Florian Jozefzoon grabbed a goal in the first minute of stoppage time to placate the locals somewhat.
NEC remain at the bottom of the pile after goals from Mohamed El Makrini and Tobias Haitz secured a 2-1 win for Camburr, who leapt out of the relegation zone with three points.
